High performance rotational devices often require high accuracy, precision bearing parts. For example, in rotating disc memory devices, drive spindles must provide increasingly higher rotational accuracy as track densities become higher. Conventional disc drive spindles use two ball bearings with a magnetic fluid seal. The rotational accuracy of these spindles is determined by the moving ball bearing parts. To achieve the track position accuracy and stability required, disc drive manufacturers typically employ complex head-positioning servo systems. However, these systems are expensive and tend to be unreliable.